The first menstrual period, the first menstrual period, varies significantly in duration and usually lasts for one week or more than ten days. The endometrium undergoes cyclic changes due to the interaction of estrogen and progesterone, and eventually sheds and bleeds to form menstruation. The first menstruation is a sign of puberty, usually at the age of 12-15 years. The duration of menstruation depends on the individual’s body type, and lasts for no more than 7 days in most women, but can last for more than 10 days in a few. In the months following the first menstruation, the ovaries are not yet fully functional, resulting in irregular menstrual cycles, unstable menstrual flow and uncertain duration. Usually after 3-6 months, the menstrual cycle gradually becomes normal. During the first menstrual period, you should pay attention to the cleanliness of the vulva and change the sanitary napkin regularly. Also pay attention to keep warm, take more rest and try to avoid spicy and stimulating, raw and cold food.